We're using Google Groups Sync to synchronize our members in CiviCRM with groups in Google Groups. However, if the user unsubscribes from the list using the Google Groups link, Google Groups Sync will automatically re-add them during the next sync cycle.
The solution, I believe, is to include the unsubscribe link CiviCRM would generate if the e-mail originated from CiviMail, but I can't work out how to generate that link.
Is it possible to generate an unsubscribe link manually, or generic enough to include in the footer of Google Groups messages?